Automatic arm



Aug. 2, m7. msmw' P. VON KIRALY ET AL AUTOMATIC ARM Filed Oct. 5, 1925Aug. 2,, EQZZ. 1,637,490

P. vow KIRALY ET AL AUTOMAT I C ARM Filed Oct. 5, 1925 2 Sheets-Sheet 2Patented Aug. 2, 1927.

PAUL VON KIRALY AND JOSEF LovAsz, or BUDAPEST, HUNGARY.

AUTOMATIC ARM.

Application filed October 5, 1925, Serial No. 60,661, and in GermanyOctober 6, 1924.

Our invention relates to automatic arms, having a barrel arranged forshort recoil. which recoil movement is transmitted to the breech boltand involves an improved transmission of the recoil momentum of thebarrel to the breech bolt, then an increased delay in the opening of thebolt and means for dislodging the spent shell by means of a front blow.

To these ends we employ a special lever mechanism, then specially formedgoverning working surfaces of the main parts of the Fig. 5 is a crosssection through the bolt.

Fig. '6 shows the working surfaces of the slide.

.the lever mechanism.

Fig. 8 shows the working surfaces of the slide with slowly increasingelevation. The corresponding surfaces of the bolt 5 are drawn withdotted lines.

Fig. 9 shows our invention as applied to a block bolt and with anunlocking lever.

Fig. 10 shows the same mechanism, but

. without an unlocking lever. The mechanism consists of a barrel 1 towhich a recoil movement of about /g- /g inch, in the case, is allowed.The spring 4 holds the barrel 1 in its foremost position and returns itthereto after each recoil movement.

The positively locked breech bolt, whlch is of the straight pull type,consists, as usual, of two main parts, the bolt 5 which supports thebottom of the shell and a slide 7 which operates the bolt.

The bolt is shown in Figs. 1-S as a turning boltbut any other boltsystem (block or looking lever bolt etc.), can be chosen.

In the form of the inventionas shown in Figs. 1-8, the slide 7. issituate'dbelow the Fig. 7 is a'lateralview of another form of.

bolt 5. It can, as a matter of course, be placed on any other side ofit, or in it, or around it.

This slide 7 carries working surfaces, of which'the one opens the bolt,the other closes it.

The opening surface 9 is shaped as a long drawn curve, rising at first,but slightly, and farther on more rapidly. (See Fig. 8). Thus, in thefirst phase of the backward movement of the slide 7 but a small fractionof the unlocking movement of the bolt is performed, the balance of itbeing done by the farther, more steeply inclined part of the surface 9.

If the recoil movement of the slide 7 must in its first phase be furtherfacilitated, then the elevation of the foremost part of the openingsurface 9 of the slide 7 can be reduced to zero, so that in that casethe opening surface 9 consists of a straight part and of a curved one(Fig. 6). It then allows to the slide 7 a free movement, within which itdoes not engage or influence the bolt 5.

The two main parts of the bolt can be made to engage one another bymeans of grooves and threads, or of lugs, 01 of an arm,

- or in any other way.

- The slide 7 is supported by a closing spring 12 by which the forwardmovement of the breech bolt is effected.

The firing mechanism can be freely chosen and constructed.

Between the barrel 1 and the slide 7, a main lever (26, 30) is inserted(Figs. 1, 2, '3, 4 and 7). This main lever can equally well be situatedeither on the barrel, or on the case, or on the slide, or on the bolt.It causes the barrel to transmit to the slide 7 the greatest part of itsrecoil momentum. For this purpose the main lever 26, 30 is so formed andso arranged that it accompanies the recoiling barrel in the first phaseof its movement without working,- so that its accelerating effect uponthe slide only makes itself felt in the last phase of the recoilmovement of the barrel 1.

Whenever the main lever is pivoted on the barrel 1, or on one of themain parts of the breech bolt, the projection 29 of the case 2 gas whichengages the short arm 28 of the main lever is placed some distance aheadof this short arm, so that this arm only can hit it in the last stage ofthe backward travel of the barrel. Thus the main lever only canaccelerme curved and so formed that the farthest end breech bolt.

of the lever touches the corresponding operating surface 31, which canbe situated either on the barrel 1 or on the bolt 5. Ac-

cordingly, during the first stage of the recoil movement of the barrelalmost no acceleration of the slide 7 takes place. Now, during thecontinued rotation of the main lever 30 its point of contact with thisoperating surface 31 shifts towards the axis of the main lever 30, theleverage increases and so the accelerating effect of the main lever 30is delayed in this case also, so that it only takes place in the lastperiod of the mood movement of the barrel.

Generally a catch 15 is situated in the case,

the object of which catch is described later on.

Figs. 9 and 10 show our invention adapted for a bolt of the blocksystem.

According to the construction shown in Fig. 9 an unlocking lever Bis'situated in the block bolt 5 and the slide 7 is provided at its rearend with a surface 8, by which the closing and locking of the bolt 5 iseffected, and with a simple lug 12 placed at a certain distance from thelower arm of the unlocking lever R in order to insert a free movementbetween the two main parts of the The relative situation of the parts ofthe breech bolt at the end of the iltmlocking movement is shown bydotted mes.

Witlf'the mechanism shown in Fig. 10, the locking and unlocking of thebolt 5 is done by means of an arm of the slide 7 which projects into arecess T of the bolt 5. This arm of the recoiling slide strikes againstthe surface 12 of.the recess T, forcing the bolt 5 downwards and sounlocking the latter from the case 2.

The length of the free movement of the main parts of the breech bolt iscontrolled by the length of the recess T.

From this description it is seen, that barrel, slide and bolt recoil atfirst together,

without any change in their relative posi tions. In a later phase of themovement of the barrel the main lever 26, 30begins to work and increasesthe recoil velocity of the slide 7. This slide leaves then the barreland recoils alone. The barrel and the bolt 5 have, in the meantime,finished their backward movement, they stand still and then begin tomove forward, the bolt 5 still being.

firmly locked with the'barrel. After some 1 3 inches of recoil movementof the slide 7, during which it did not yet unlock the.

bolt, the surface 9 of the slide gets engaged with the correspondingsurface of the bolt and only now, long after the barrel has absolved itsrecoil movement and after the main lever 26, 30 has displayed itsaccelerating effect, does the slide 7 open and rei'ect the bolt 5. Thebolt 5 being uncontro led by any closing spring, recoils freely andextracts and ejects the empty shell.

So the main lever 26, 30 does not work on the bolt, but on the slidewhich thus receives and accumulates the recoil momentum of the barreland utilizes it in a later moment, for operating the bolt 5.

It is also seen that the transmission of the recoil energy of the barrelto the slide, then the opening of the bolt by the slide both areperformed in dilferent moments and by means of semielastic shocks. Inorder to make the best use of these shocks, certain correct proportionsmust exist between the masses of the barrel, of the slide and of thebolt, as well as of the weight of the whole arm or else'the breech boltwould not work correctly. If these proportions be correctly chosen, thenthe bolt 5 generally arrives in good time at its rearmost position inorder to avoid being prematurely driven forward by the returning slide.In such cases, when a belated arrival of the bolt 5 in its rearmostposition is inevitable, we employ a catch 15 which catches the returningslide 7 and retains it until the recoiling' bolt 5 depresses the nose 18of the catch 15 and with it the catch 15 itself and thus releases theslide 7. Then the breech bolt is closed by the main spring 12.

The catch 15 can serve as interrupt0r also,

24 in a manner that, when depressed, it shifts the link 23 forward,until it releases the sear 24 which can then correctly re-engage thehammer.

The catch 15 can well be emplo ed to support by its forearm 16 and slide7 in its foremost position. In this case, the catch 15 can be made useof as a safety device which prevents premature firing of the arm,'because it only releases the link 23 of the sear, in its uppermostposition that is, when the bolt is completely closed.

Another useful feature of the breech bolt mechanism we have described isthe fact that the very economical utilization and gradual transmissionof the recoil momentum of the moving parts results in a weak and veryelastic recoil of the entire arm, more so indeed, than is the case withmost other automatic-arms. Consequently we can make arms of very lightweight, or shoot more powerful cartridges from rifles of the usualweights.

Having now particularly described and ascertained the nature of our saidinvention and in what manner the same is to be performed, we declarethat what we claim is:

1. In an automatic fire arm having a barrel arranged for short recoiland a bolt, the

' Combination with the barrel of a bolt actuating slide and a lever toactuate the slide, the lever being adapted to receive and to transmit tothe slide the impact of the recoiling motion equal to more than twicethe total recoil movement of the barrel, before the bolt isactuated bythe slide.

2. An automatic fire arm as claimed -in claim 1, in which the operatingsurface of the slide by which it effects the opening of the bolt ends ina recess by which the'un-.

locking movement of the bolt is positively limited and the opening ofthe bolt is efi'ected by a blow.

3. An automatic fire arm, as claimed in claim 1, in which the slide hasa closing surface, inclining at an angle which is greater than the angleof the opening surface.

4. An automatic fire arm, as claimed in claim 1, in which the weight ofthe slide is 1/5-1/3 of that of the barrel, or at least 1/10 of that ofthe total weight of the arm and the weight of the bolt is 1/1,51/4 ofthat of the slide thus providing proportions on which directly dependsthe functioning of the bolt mechanism. 7

5. An automatic fire arm, as claimed in claim 1, including a catch,pivoted in the case when in its rearmost position and retains it untilthe recoiling bolt presses the catch out of engagement with the slide.

In witness whereof we afiix our signatures.

JOSEF LovAsz. PAUL VON KIRALY.

and having a hose which engages the slide

